Serotonin Syndrome Risk Calculator

Assesses risk of serotonin syndrome/toxicity based on serotonergic drug combinations and clinical presentation. Uses both the Hunter Serotonin Toxicity Criteria (for diagnosis) and the Sternbach criteria (for broader risk identification).

e.g., SSRI + MAOI, SSRI + tramadol, SSRI + linezolid, SNRI + triptan, etc.

Note: The differential diagnosis includes neuroleptic malignant syndrome (NMS), malignant hyperthermia, anticholinergic toxicity, and sympathomimetic overdose. Key distinguishing features: clonus and hyperreflexia favor serotonin syndrome; bradykinesia/rigidity with lead-pipe rigidity and normal reflexes favor NMS.

References

  1. The Hunter Serotonin Toxicity Criteria: simple and accurate diagnostic decision rules for serotonin toxicity. QJM: An International Journal of Medicine (2003). https://pubmed.ncbi.nlm.nih.gov/11704718/
  2. The serotonin syndrome. American Family Physician (2004). https://pubmed.ncbi.nlm.nih.gov/15378619/
  3. Serotonin Syndrome: Pathophysiology, Clinical Features, and Management. Drugs (2004). https://pubmed.ncbi.nlm.nih.gov/15139738/
Medical Disclaimer

This calculator is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a qualified healthcare provider with any questions you may have regarding a medical condition.

  • This calculator aids clinical judgment but does not replace it. Serotonin syndrome is a clinical diagnosis.
  • Hunter criteria have higher specificity than Sternbach; use Hunter when clonus is assessable.
  • Severe serotonin syndrome (temperature >41.1°C, severe hypertonia/rigidity) is a medical emergency requiring ICU-level care.
  • Always review all medications including over-the-counter and herbal products for serotonergic activity.